<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<script type="text/javascript">
			/*
			 题目： 输入两个数，然后交换着两个数，再输出他们交换后的结果。
			 */
			
			var num1 = 20;
			var num2 = 10;
			var tmp = num1;
			num1 = num2;
			num2 = tmp;
			
			alert("num1:" + num1 + ", num2:" + num2);
		</script>
		<title></title>
	</head>
	<body>
		
	</body>
</html>
